Bio-Rad Bio-Plex Pro™ Human Isotyping Assays - Manual (Page 4)

Principle
Technology
The Bio-Plex
® suspension array system is built upon the three core
elements of xMAP technology:
n
Fluorescently dyed microspheres (also called beads), each with a distinct
color code or spectral address to permit discrimination of individual tests
within a multiplex suspension. This allows simultaneous detection of more
than 100 different types of molecules in a single well of a 96-well microplate
n
A dedicated flow cytometer with two lasers and associated optics to
measure the different molecules bound to the surface of the beads.
The Bio-Plex
® MAGPIX ™ uses LED and CCD technology to accomplish
the same
n
A high-speed digital signal processor that efficiently manages the
fluorescence data
Assay Format
Bio-Plex Pro
™ assays are essentially immunoassays formatted on
magnetic beads. The assay principle is similar to that of a sandwich ELISA
(Figure 1). Capture antibodies directed against the desired biomarker
are covalently coupled to the beads. Coupled beads react with the
sample containing the biomarker of interest. After a series of washes to
remove unbound protein, a biotinylated detection antibody is added to
create a sandwich complex. The final detection complex is formed with
the addition of streptavidin-phycoerythrin (streptavidin-PE or SA-PE)
conjugate. Phycoerythrin serves as a fluorescent indicator, or reporter.
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